
//水池放水
//一次注入3个单位的水
//一次放出2个单位的水

public class Container {
    static int water_container = 0;

    public void addition_container(){
        water_container += 3;
    }

    public void reduce_container(){
        water_container -= 2;
    }

    public static void main(String[] args){
        Container use = new Container();
        use.addition_container();
        use.reduce_container();
        System.out.println("水池的水量剩余："+Container.water_container+"单位");
    }
}
